Metal drawing lubricant



United States Patent METAL DRAWING LUBRICANT Everett C. Hughes, ShakerHeights, and Harrison M. 'Stine, Lyndhurst, Ohio, assignors to TheStandard Oil Company, Cleveland, Ohio, a corporation of Ohio No Drawing.Filed Nov. 9, 1956, Ser. No. 621,214

1 Claim. (Cl. 252-48) The present invention relates to a method ofdrawing metals such as in the cold drawing of steel rods and the drawingof aerial bomb noses and to an improved lubricant for such operations.

, Drawing involves the plastic deformation of metal by a hard steel die.High temperatures and pressures are generated between the die surfaceand the metal being drawn, and sutficient lubrication is required inorder to prevent adhesion of the metal to the die surface and to preventscratching and tearing of the surface of the drawn object. It isnecessary for drawing fluids to cool the metal, reduce friction, anddiminish seizure. Ease of application and removal of the drawing fluidfrom the surface of the metal are also important considerations.

Heretofore, mineral lubricants, fatty lubricants, soaps and waxes havebeen used to provide lubricating films for this type of operation, and atypical drawing compound of the prior art may include sulfurized olein,castor oil and sodium soap. Inert solid materials such as calciumcarbonate have also been used as components of lubricating compositionsdesigned for metal drawing operations and have proved to be of greatvalue in forming a solid film between the metal and the die, therebypreventing metal to metal contact under high pressures.

Metal drawing compounds are customarily supplied to the trade asrelatively viscous compositions some of which are intended to be dilutedwith oil and others to be diluted with water-as dictated by theparticular requirements in each mode of use. A drawing compoundcontaining an inert solid material, such as calcium carbonate, which canbe diluted satisfactorily with either oil or water is desirable. Such acompound must possess the following characteristics:

(1) It must be capable of dilution with oil without settling of theinert solid material.

(2) It must be capable of dilution with water and capable of holding theinert solid material in suspension.

(3) It must' remain the proper consistency when has not been solved.Inert solid materials such as calcium carbonate are not readilysuspendable in water and the problem of obtaining a good suspension, inthe case of a drawing compound, is complicated by the requirement thatthe drawing compound be dilutable also with oil.

Another complicating factor is that the compound must be of suitableviscosity for dilution.

In accordance with this invention, there is provided a drawing compoundwhich can be diluted with either oil or water to provide a highlysatisfactory lubricant for drawing operations. The lubricants thusprepared provide both oiliness lubrication and solid film-type lubrlcaincertain proportions to provide a formulation which meets all of theaforesaid requirements. The compositions include a suspended phase and asuspending phase. The suspended phase includes bentonite and an inertsolid material having a hardness of 13.5 on Mohs scale. The suspendingphase includes a mineral lubricating oil and an emulsifying agent. Theproportions of the ingredients must be so balanced that the suspendedphase comprises from 60-75% by weight of the composition and thesuspending phase from 40-25% by weight of the composition.

The mineral oil used in the formulation may be any mineral lubricatingoil such as conventionally refined neutral oil, solvent extracted oil orany lubricating oil having a viscosity within the range of about 50 toabout 500 Saybolt Universal seconds at F. The mineral oil is generallythe major ingredient of the suspending phase and may comprise from about50-88% by weight of the suspending phase. The mineral oil serves a dualrole in the composition. It is both a carrier for the inert solidmaterial and it is an auxiliary lubricant.

The emulsifying agent can be any of those surface active agents whichare commonly used in the preparation of emulsions, particularlyoil-in-Water emulsions, such as alkali metal, ammonium or hydroxylaminesalts of fatty acids, petroleum sulfonates including long chain alkylsulfates and alkyl-aryl sulfonates, polyoxyethylene derivatives ofphenols, alcohols, etc., and the like. Preferred emulsifying agents arethe sodium salts of petroleum sulfonic acids having molecular weightsbetween 375 and 525. In addition to the emulsifying agent, emulsionstabilizers such as glue or gelatin may also be employed.

The amount of emulsifying agent is not critical. Any amount thatemulsifies oil in water in the usual range of dilution intended for thedrawing compound of this invention may be employed. Generally, it ispreferred to employ from 1250% of the emulsifying agent based on theWeight of the suspending phase. When petroleum sulfonates are used asthe emulsifying agent. the maximum amount to be employed is limited bythe viscosity to the composition, because petroleum sulfonates arerelatively viscous materials. However, higher concentrations ofpetroleum sulfonates can be used with mineral oils in the lower part ofthe viscosity range given herein above.

Among the inert solid materials which may be used are those which aresubstantially insoluble in water or oil and have a hardnessof 1 to 3.5on Mobs scale of hardness. Such substances include calcium carbonate,zinc sulfide, lithopone, talc, and other types. of clay. The inertmaterial is employed in finely divided form and is preferably fineenough to pass a mesh screen.

A hydrophilic bentonite is employed to maintain the inert solid, such ascalcium carbonate, in suspension in the suspending phase of the mixture,after dilution with water, as a result of the formation by the water andthe bentonite of a thixotropic gel. The bentonite employed is preferablyground to a fine, odorless gritfree powder, having a particle sizesufiiciently small to pass a 200 mesh screen. For the purpose of thisinvention, it is necessary that the bentonite be in its natural state asin this state it is highly hydrophilic. Organ'ophilic bentonites are notsuitable for the purposes of this invention.

'Bentonite and the inert solid material together comprise the suspendedphase. The inert solid material comprises the major ingredient of thesuspended phase and is preferably employed in amounts rangingfrom.85-97.% by weight of the suspended phase and the bentonite .inamounts ranging from 15-3% by weight of thesuspended phase. E

A most important factor in the compositions of. this invention is theproportion of the suspending phase" to the suspended phase which iscontrolled by the consistency of the composition and its stabilityagainst separation into two phases. It has been found, for example, ha ac n entra io i h of he su nd d f he ximm, amou t t at c n, be o a d oproduce acomposlition with a workable consistency to per.- f ss f rr n"n. th t er, han abo 60% y tl Qf the suspended phasewas found. tobelowereau e omp si s s onta n s Q1 m t e 'efd, 'e aratiqn.q o lpro on sdtandina e dilution of the. drawingc'ompound of this inventedonly by thestability of. the suspensionof; a a n th Q n asaq he qr l iqn- It hasbeenfound thatthe drawing compound may be diluted wit se eral mes ts wnWe g f. i he oil te Gen, owever, the de gree ot dilution will be he qsiv. dcsi d a h i ular haw-ins .n at qn o. he .p ftt me preferredlubricating composition consists of 18%. e sht f, q itim llrfin neu al.o 2%. y. t. stenc l b i mupq o eum fo at of hae fi hdgany acidtype suchas, hoseavai a e e i the t rade v names, Petronate, Retromix No. 9, andHardesty Basel-9,? 64% by weight of precipitated .calciumcarbonate, and6% I by weight of a natural bentonite. invention; will be. furtherillustrated by reference tg the following specific examples:

n EXAMPLE: 1

One hundred pounds of a soluble oil consisting of (39% weight of aconventionally refined neutral oil having a. viscosity of lQOSUS' at 100F and 40% by of. an enuils ifying agent composed of a sodium petroleumsul fonate having a molecular weight ofvabou t were placed; in a vessel.Twohundred ten pounds of precipitated calciumcarbonate and pounds ofatura .v bea i e gro nd, o; Pa mesh creen were, slowly added to thesoluble .oi l While agitating the ixture it n -barre size L h n m e Asmoothcreamy paste resulted.

The u i a compoun was lu e r, us n a drawingpperation with 1% volumes ofwater per volume a drawin w n EXAMPLES ,2 THROUGH- l2 Aeseries offormulations preparedusing the procedure andingredientsof Example 1. Theproportions of ingredients and observations. appear in the followingtable! p Allofatl e. compositionstor Whiihdata are given in Tabled..have.proved ;to-,he satista ctory. It. is desirable that thecompositions prior to dilution have a viscous paste-like consistency sothat they may be easily admixed with water or oil and thischaracteristic is possessed by the undiluted compositions of Examples 2,7, 8, and 9. Similarly, it is desirable that the compositions, beforedilution, be stable againstseparation of the two phases and this propey; als is po es ed y he wmpositions of Examples '2, 7, 8, and 9. Itshould be noticed that bleeding; is a-jfatal defect: if the compositionscan be readilyv redisper sed. Although some bleedingoccurred in thecompositions of 'Examples '7, 8, and 9; the composii n a e, neuenhe ssawspt hle sqaus the ea i redispersible.

After dilution, it-is desirable that" the diluted compositions have aconsistency somewhat like that of heayy cream andall'of ihe dilutedcompositions, i.e. Examples 3, 4, 5 6', 10, 131, and 12-,jhavedesiredconsistency. Similarly, 'the diluted compositions also must bestable against separation into two phases,i',e. a suspendedph ase id 8usi n ne ase 7 0? he .d ed'a m q q are satisfactory in this respect;Itis noted that-a slight amount of calcium carbonate precipitated to thebottom of the compositionsqf- Examples l1" and'-1 2 on standing.Hgwever, -tl;je amount of' precipitate was so, small as 1 156. ne g b ean v no ie t a b The examples adequately illustrate the adaptability ofthercon p ositions of thi s invention to dilution with either a l, orq in flie. wmrao t a s a r t y a 'i s not possessed by competitiveproducts. A Q

es f, he ubr ca n qmp a n. aw ne a r i ns. shawsd he qmp u ds o h r atisr t fv oth h n i uted w wa e aa i h. il n s. o ra isu nvolv n he. r w aof o s s he. tee new ith ut. rink n Q br a a t nd PQ iS iQEV qffliediswa 7 eq i e i tinalhe ntir e tr r dn m lsion nre at sl fr m. h lubrisatns c oa nosit n ofEiwtnpl n r n ed atisfac qril nf e rawia of,rods,fronr0.; inch to 0,63 inch. i

t r e obv ou ths ic. kil s r a the rt h tman modifications maybe madewithin the scope of the pre en on ithout. dsaa tias rsznaths s iri he aza a t staistqbslrestri tediuasw daa c ,qa Q i h da sa s.

An inul ifia le. ubfic im rz sitian compris n .0 to 75%.hvweiehtnf,asusn ade phase cns s inaes m ia v f, boutisfi c y. ei h -o a ue ts Zdlmater al ,selestetl f tn. the r u w sis s.v of .cal carbonate, zincsulfide, lithopone, ;ant1 ?l. havinga d; ess .1. p nMohs. a e an apar ce s e te fi enough to p 591mm. sm aaaBdabQQtJ19 Table-l [Wtapercentconcentrationbt components} Dilution on v01. 7 My 0500 'Bent ntte Enlslfy St bill s' o ,@m :a t ExampleNo. ,(Ground), .200 mesh. lug Agent011, C.R.N.eutral 1 isiin aiiiii mesh.. VoLQlb Vol. H 0 (DiamondParaffin a 67.0 6.31 10.7 16.6.... t 67.0., 6.13 10.7 16- verwettstacgory (he vy-cream.

V conssenc 67.10 6.3 10.7 16 3., isattstactoriiy' 67.0 6.3, 10.7 8Satlstactoxyteasfly.dispersed). 66.9 6.4- 5.3 Nagy sagistact'ory(overnight 7 7 ea, in; 66.9 6.4 5.8 21.4 1695 gleedin g (readily redlsparse 66.!) 6,4. 5.3. sn g- 1 1.4 S,.E. 10% bleedingcneadlly *il'elusq:

parse 66.9 V 6.4 4.3- 22.4S.E. 500sec. I I 118% bleeding (readily redis-63 5' 61 i 122 13 3 1 v iirt' V i M x --.a sanacor. 63.5- 6.1 12.218.3-. 3 sll amountf of-carbgnate at 63. 5 5.1 x 12.2 ms a -1 6References Cited in the file of this patent UNITED STATES PATENTS CrossDec. 17, 1929 Adams Aug. 16, 1932 Rader Aug. 6, 1940 Zimmer Oct. 7, 1941Roden Dec. 14, 1954 Reamer Nov. 1, 1955 Spring Aug. 28, 1956

